This application relates to a transfer bearing for a gear reduction in a geared turbofan, wherein the oil leakage at axial ends of the bearing is controlled.
Gas turbine engines are known and include a fan delivering air into a bypass duct as propulsion air and into a core engine, where it flows to a compressor. The air is compressed in the compressor and passes downstream into a combustor section where it is mixed with fuel and ignited. Products of this combustion pass downstream over turbine rotors driving them to rotate. The turbine rotors, in turn, drive the compressor and fan rotors.
Historically, a turbine rotor drove the fan rotor at a single speed. More recently, it has been proposed to include a gear reduction between a fan drive turbine and the fan rotor.
The gear reductions require adequate lubrication. In one gear reduction, a fan drive shaft is driven by a rotating carrier in a planetary gear system. A transfer bearing provides oil to the carrier.
The transfer bearing supplies oil through a plurality of passages in the carrier, such that oil is supplied to gears and journal bearings within the gear reduction.